The bomb squad and police surrounded the home of Radcliffe and Zina Haughton in Brown Deer on Sunday, and it wasn't the first time they had been there.

"All we observed were the Brown Deer police coming to the house more than once -- at least three or four times that I know of," neighbor Allen Pankow said.

Pankow lives doors away from the Haughtons' home.

"He was a very large man, and he had a very fast temper," Pankow said.

Police said Haughton walked into the Azana Salon and Spa looking for his estranged wife, Zina. The shooting ended a history of domestic incidents.

Court documents show police were involved in a standoff with Radcliffe Haughton at the home on Jan. 8, 2011.

The complaint said he "threw his wife's clothes and bedding in the yard and poured tomato juice on his wife's vehicle," and then "...pointed a long-barreled black object out the window (and) at Zina who stood 3 feet away from officers outside."

The standoff "ended peacefully when officers left the scene," the complaint said.

Brown Deer's police chief spoke Sunday about prior calls at the home.

"We have had contact with him in the past," Chief Steven Rinzel said.

Rinzel wouldn't speak Monday, but in a statement defended his department's actions, saying they left because "...Zina Haughton, was uncooperative during our investigation."

She told police that day that she was not fearful for her safety.

Police said Zina also claimed at the time that her husband did not have any weapons.

Some in the Brown Deer neighborhood reportedly had run-ins with the suspect at his home.

Four people, including Zina and Radcliffe Haughton, were killed Sunday. Four others were injured.

Brown Deer police said Monday that the ATF discovered Radcliffe purchased a .40 caliber handgun from a "private citizen" on Saturday. No other weapons were found in his home.